Ukraine will top off its natural gas reserves during the summer with increased purchases from Russia, dpa quoted Prime Minister Yulia Tymoshenko as saying today. The former Soviet republic will spend 250 million dollars on increased imports in July, and as much as a billion dollars in August and September combined, so that underground reservoirs are near maximum capacity before the onset of cold weather, Tymoshenko said, according to an Interfax news agency report. Tymoshenko's announcement came less than a week after European Union officials in Brussels and Kiev publicly expressed doubt Ukraine could pay its gas bill to Russia due at the end of June, and against a background of repeated calls from Tymoshenko's government for more foreign credit. Tymoshenko spokesmen Monday predicted Ukraine's state-owned natural gas transport company Naftogaz Ukrainy, the firm responsible for Ukraine's gas pipeline system, could go bankrupt in a matter of weeks, without approximately 600 million dollars in emergency loans to cover a mounting debt to Russia. Tymoshenko's government is grappling with rising internal debt as well, currently estimated at 3.4 billion dollars, according to estimates by independent analysts. Kiev has asked the EU for a 4.2-billion-dollar loan to help close a rising budget deficit, and to cover the cost of further gas imports from Russia. Large-scale gas purchases were best made immediately, Tymoshenko said, as the price of natural gas sold to Ukraine from Russia is pegged to the price of crude oil, which has been rising steadily. Disputes between Russia and Ukraine on the terms for transporting Russian gas to Europe via Ukrainian pipelines broke down in early 2009, causing a three-week Russian total gas export embargo to Ukraine. The blockade, cutting off Europe from approximately one quarter of its natural gas needs, spiked prices as far away as Spain. Ukrainian officials led by Tymoshenko herself have argued Ukraine must receive more loans, in order to prevent a repeat embargo.